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Multilingual Retrieval Using Thesauri Alignments

The project targets the Semantic Web representation of relations between keywords in the German Schlagwortnormdatei (SWD) and classes in the Dewey-Decimalclassification (DDC). SWD and DDC are used by German and international libraries for annotating their collections and making them accessible. The relations between SWD and DDC will allow for searching DDC annotated collections with keywords from SWD and vice versa.

The relations between SWD and DDC have a high quality because they have been manually created in the context of the CrissCross project. But often the meanings of SWD keywords and DDC classes do no match exactly. This is the reason why each relation has a certain deterministic level which provides information about the strength of the relation. The relations and the deterministic level can be used by information retrieval systems for adjusting precision and recall.

These relations are going to be published in the course of the linked data activities of the German National Library. It is going to be based on the SKOS specification. But the existing mapping relations in the SKOS specification are not suitable for representing the different deterministic levels.

This project will start with analyzing the existing deterministic levels and their implications for information retrieval. Furthermore, a recommendation will be worked out how the existing SKOS specification may be extended in order to be capable of representing the deterministic levels of the CrissCross relations.


  • March 2010 - June 2010


  • German National Library


  • TBD